counselling programme in general practice. Method Prospective cost-effectiveness study undertaken as part of a cluster randomised controlled trial with ...
THE NEW ZEALAND MEDICAL JOURNAL Vol 117 No 1207 ISSN 1175 8716
Cost-effectiveness of physical activity counselling in general practice Raina Elley, Ngaire Kerse, Bruce Arroll, Boyd Swinburn, Toni Ashton, Elizabeth Robinson Abstract Aim To assess the cost-effectiveness of the ‘Green Prescription’ physical activity counselling programme in general practice. Method Prospective cost-effectiveness study undertaken as part of a cluster randomised controlled trial with 12-month follow-up of 878 ‘less-active’ patients aged 40-79 years in 42 general practices in the Waikato. The intervention was verbal advice and a written exercise prescription given by general practitioners, with telephone exercise specialist follow-up compared with usual care. Main outcome measures included cost per total and leisure-time physical activity gain from health-funders’ and societal perspectives. Results Significant increases in physical activity were found in the randomised controlled trial. Programme-cost per patient was NZ$170 from a funder’s perspective. The monthly cost-effectiveness ratio for total energy expenditure achieved was $11 per kcal/kg/day. The incremental cost of converting one additional ‘sedentary’ adult to an ‘active’ state over a twelve-month period was NZ$1,756 in programme costs. Conclusion Verbal and written physical activity advice given in general practice with telephone follow-up is an inexpensive way of increasing activity for sedentary people, and has the potential to have significant economic impact through reduction in cardiovascular and other morbidity and mortality. There is now substantial epidemiological evidence to implicate a sedentary lifestyle as a risk factor for obesity, diabetes, cardiovascular disease, depression, bowel and breast cancer, and various other disease states.1–4 Existing evidence suggests that at least 30 minutes of moderate activity on most days of the week is associated with significant health gains and has led to major position statements such as the 1996 US Surgeon General’s report on physical activity and health. 4 In New Zealand, one-third of adults do not undertake the recommended 2½ hours of moderate-intensity physical activity per week.5 As a result, the Hillary Commission developed the Green Prescription physical activity counselling programme for New Zealand primary healthcare. A randomised controlled trial to assess the effectiveness of the programme in the Waikato region found that the programme was effective in increasing physical activity and improving quality of life over a 12-month period.6 However, the cost-effectiveness of the intervention was not known. The aim of this study was to calculate the incremental cost-effectiveness of the Green Prescription programme in increasing physical activity compared with ‘usual care’ in general practice, and to compare this with other community-based physical activity interventions reported in the literature.
NZMJ 17 December 2004, Vol 117 No 1207 URL: http://www.nzma.org.nz/journal/117-1207/1216/
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Methods Background The cost-effectiveness analysis of the Green Prescription programme was incorporated prospectively into a cluster randomised controlled trial undertaken from mid-2000 to mid-2002.6 General practices in the Waikato region of New Zealand were randomised to give the Green Prescription or ‘usual care’ to patients enrolled in the study. Baseline and 12-month follow-up measurements were taken at each practice by research staff. The cost-effectiveness analysis was undertaken from health funders’ and societal perspectives. The Waikato Ethics Committee approved the study in 1999.
Participants Consecutive 40 to 79 year-old patients were screened at the reception area of 42 rural and urban general practices over a 5-day period. Those not achieving the recommended 2½ hours of at least moderate activity per week were invited to participate in a study involving a lifestyle intervention.
Intervention Study participants from intervention practices prompted the general practitioner or nurse to give verbal advice to increase physical activity with activity goals written on a Green Prescription. Patients from control practices received usual care. The Green Prescription was then faxed to exercise specialists in Sports Foundations who provided telephone support on three occasions over the following three months to each intervention patient and sent written material including newsletters.
Measures Primary outcome measures in the clinical trial were change in leisure-time physical activity, total energy expenditure, quality of life (using the SF36 scales), 4-year coronary heart disease risk, and systolic and diastolic blood pressure. A post-hoc analysis comparing the proportion of participants that achieved 2.5 hours of leisure activity was carried out to allow comparison with previous studies carried out in primary care.7 Primary outcomes measured for the cost-effectiveness study were the incremental cost of change in selfreported physical activity over 12 months. These outcomes included the cost per total energy expenditure gained, the cost per leisure moderate- and vigorous-intensity energy expenditure gained, and the incremental cost of moving one additional ‘sedentary’ person into the ‘active’ category (achieving 2½ hours of at least moderate-intensity leisure activity per week). Costs—Green Prescription programme development costs incurred in previous years were obtained from the developers of the programme, the Hillary Commission, and were adjusted for inflation using the December consumer price index from each corresponding year compared with that of December 2001.8 A discount rate of 5% was used to calculate present equivalent values of programme costs from 1996 to 2001.9 Programme delivery costs included general practitioner and practice nurse time, Sports Foundation exercise specialists, and Green Prescription resources. Delivery costs within the general practice were estimated using usual consultation charges for participating practices, national award rates for practice nurses, and the time, estimated as 7 minutes by general practitioners and 13 minutes by practice nurses, for programme delivery.6 Charges for each general practice in the region were obtained at baseline and average charges calculated for each consultation type. Actual regional Sports Foundation personnel and overhead costs associated with the programme were obtained from the Sports Foundation’s accounting department for the year 2001/2002. Average wage costs rather than marginal costs were used as the exercise specialists were permanent staff of the Sports Foundation. Offset cost—Self-reported costs to the individual associated with exercise were identified by study participants in a 12-month follow-up questionnaire and included exercise equipment purchased, sports club or exercise group subscriptions, travel expenses to and from exercise, and any other costs associated with exercise over the 12 months of the study. Costs associated with primary and secondary healthcare utilisation and costs of time off work were also recorded. Primary healthcare offset costs were calculated for each participant for the 12 months prior to study enrolment and compared with the 12 months after study enrolment. Actual number and type of
NZMJ 17 December 2004, Vol 117 No 1207 URL: http://www.nzma.org.nz/journal/117-1207/1216/
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general practice consultations were obtained from practice records. Actual government subsidies for each type of consultation were used and were adjusted for inflation. Patient charges and subsidies vary. Average patient part-charges of participating practices were used for consultations of non-subsidised patients (A3) (NZ$35) and low-income (A1) or high-user patients (AZ) (NZ$20), and for accident-related consultations NZ($10). Government subsidies for each consultation were NZ$15 for A1 and AZ visits, and NZ$26 for all accident-related visits. Numbers of accident-related visits to physiotherapists, chiropractors, and osteopaths were obtained from patient questionnaires. These visits were subsidised at a rate of NZ$19 per visit, with an average patient surcharge of NZ$10. Secondary care costs were established using each participant’s national health index, a unique identifier in primary and secondary healthcare allowing tracking of individual’s health care utilisation. Actual hospital inpatient, outpatient, and investigation costs for each patient from all public regional and base hospitals were obtained from the local district health board for the year prior to and the year following each patient’s enrolment in the study. Costs for private hospital-use could not be obtained. However, self-reported private hospital admission-rates were recorded. To calculate the cost of loss of productivity due to illness and accident for the year prior to baseline compared with the year after baseline, the change in the number of days of illness- and accident-related leave taken were obtained by self-report. The average wage for the June quarter from wages, salary, and self-employment for those in paid employment was NZ$121.80/day for 2000 and NZ$128.20/day for 2001.10 All costs were adjusted for inflation using the 2001/2000 consumer price index ratio to calculate the incremental change. All costs are reported as New Zealand dollars. Where comparisons with programmes from the United States or the United Kingdom were carried out, values were converted to the New Zealand dollar according to the exchange rate of December 2001.11
Analysis Total setup and programme administration costs were obtained to calculate programme cost per patient. Actual offset costs of primary and secondary healthcare utilisation, personal expenditure, and productivity changes were collected wherever possible. The differences in change in offset costs to the patient and health funder for intervention patients compared with control patients, with 95% confidence intervals, were calculated using a random effects generalised least squares regression model, where the general practice was entered as the clustering variable in STATA version 7.0. Cost-effectiveness ratios were obtained by calculating programme costs per activity gain from a programme-funder perspective. These ratios were compared with those from other physical activity interventions reported in the literature. Sensitivity analyses were conducted using the confidence intervals for calculated physical activity gains as the relevant range.7,12 All analyses were carried out using an intention-to-treat approach, where no change from baseline was assumed in those who did not attend follow-up, except personal costs associated with exercise, where costs were assumed to be the mean of those in the equivalent group.
Results Table 1 shows the characteristics of the 878 study-participants from 42 practices.6 Results from the randomised controlled trial, which achieved 85% follow-up at 12 months, showed a mean total energy expenditure increase of 9.4 kcal/kg/week (p=0.001) and leisure exercise increase of 2.7 kcal/kg/week (p=0.02), or 34 minutes/week more in the intervention group than in the control group (p=0.04).6 SF-36 scores of self rated ‘general health’, ‘role physical’, ‘vitality’, and ‘bodily pain’ improved significantly more in the intervention group (5.95, 10.53, 5.36, and 6.51, respectively) compared with the control group (1.60, 4.16, 3.06, and 2.50, respectively) (p
